physical examination of water in civil engineering

The physical examination method of water includes the following tests:

1. Temperature test in water. 

The temperature of water during water birth is measured by an ordinary thermometer. It helps in determining the density of water, viscosity of water, vapour pressure of water and surface tension of water. The maximum permissible temprature of water for domestic supply is 10°C to 15°C.


water temperature testing thermometer
water temperature adapter


2. colour test in water. 

The color of the water indicates the source of the water and has little hygienic significance. Color may stain materials, complicate coagulation in treatment and may affect some industrial process.


platinum cobalt color scale
different colour according platinum cobalt scale


    The color of water is expressed in numbers on the platinum cobalt colour scale. The maximum permissible color of water for domestic supply is 10 to 20 ppm (parts per million) on the platinum cobalt scale.

3. turbidity testing of water.

Turbidity is a measure on the resistance to the passage of light through water. Water is said to be turbulent when it contains visible material in suspension. This is due to the presence of suspended and colloidal matter in water. It is expressed in ppm. The maximum permissible turbidity for domestic supplies is 5 to 10 ppm on the silica scale. Is. on the silica scale

digital turbidity meter
digital turbidity sensor meter


 The turbidity of water is measured by the following methods:

(a) turbidity tube measurement

(b) Jackson Turbidity Meter

(c) Bayliss Turbidimeter

(d) Helip Turbidimeter.

Low turbidity of water can be determined by Bayliss turbidimeter and high turbidity of water (above 50 ppm) can be determined by Jackson Turbidity Meter.

4.taste and odour test of water. 

Taste and smell can be due to the presence of microorganisms either dead or alive, dissolved gases like oxygen, carbon dioxide, methane etc. and mineral substances like sodium chloride, iron compounds etc.

       The smell of water varies with temperature. The smell of water is tested at 20 °C to 25 °C. The instrument used to measure odor in water is called an osmoscope. A commercial osmoscope is graduated with a pO value from 0 to 5. Different PO values ​​define the following meanings: